Polydopamine-assisted dip-and-dry fabrication of highly conductive cotton fabrics using single-wall carbon nanotubes inks for flexible devices

We have successfully fabricated electrically conductive cotton fabrics with a low sheet resistance. The electrically conductive fabrics have attracted much attention as materials for flexible devices. We used N, N-dimethyl-formamide (DMF) as a solvent, in which single-wall carbon nanotubes (SWCNTs) were dispersed without any dispersants. The electrically conductive cotton fabrics were fabricated using a simple polydopamine (PDA)-assisted dip-and-dry method. The electrically conductive fabrics were characterized by micro-Raman spectroscopy and scanning electron microscopy. The low sheet resistance of 9 ± 2 Ω/sq was achieved for electrically conductive cotton fabrics using DMF-SWCNT inks. Moreover, we demonstrated the electromagnetic interference (EMI) shielding effectiveness (SE) using the fabricated electrically conductive cotton fabrics. The EMI SE and return loss were measured in the two frequency ranges (4–6 and 8–12 GHz) using waveguides and a vector network analyzer. The measured SE was about − 30 dB. The fabricated electrically conductive DMF-SWCNT-PDA cotton fabrics fulfilled the requirement for the practical EMI shielding.